package extend;

public class Animal {
    void call(){
        System.out.println("动物");
    }
    void eat(){
        System.out.println("动物吃");
    }
}
class Dog extends Animal{
    void call(){
        System.out.println("狗");
    }
    void eat(){
        System.out.println("dog吃");

    }
}
class Main{
    public static void main(String[] args) {
//        Animal animal=new Dog();
//        animal.call();
//        animal.eat();
//        System.out.println(args.length);
//        String s1 = "abc";
//        String s2 = s1;
//        String s5 = "abc";
//        String s3 = new String("abc");
//        String s4 = new String("abc");
//        Long l1=127l;
//        Long l2=127l;
//        System.out.println(l1==l2);
//        System.out.println("s1 == s5 : " + (s1 == s5));
//        System.out.println("s1 == s2 " + (s1 == s2));
//        System.out.println("s1.equals(s2) : " + s1.equals(s2));
//        System.out.println(" s3 == s4 : " + s3 == s4);
//        System.out.println("s3.equals(s4) : " + s3.equals(s4));
    }
}